A Technical review on Design Challenges of 60 GHz Wireless Communication System

IJSTE - International Journal of Science Technology & Engineering | Volume 2 | Issue 08 | February 2016 ISSN (online): 2349-784X

A Technical Review on Design Challenges of 60 GHz Wireless Communication System Sumesara Urmila Mansukhbhai PG Student Department of Electronics & Communication L.D College of Engineering, Ahmedabad

Prof. Suresh L. Bharvad Associate Professor Department of Electronics & Communication L.D College of Engineering, Ahmedabad

Abstract 60-GHz wireless communication system will become the world’s first massively wireless broadband millimetre wave propagation system. The data rates and bandwidth provided by this band are excellent. If we add all bandwidths currently used by all wireless communication systems then it will represents only a small percentage of total bandwidth available on this 60 GHz band. Therefore it can be a good solution for future 5G technology for mobile communication. But this band will face some design challenges which makes this band difficult to implement in consumer market. In this paper, we have presented literature review of papers which have shown different design challenges faced by 60 GHz band. Some major design challenges of 60 GHz band are high path loss, rapid variations in the channel, high power requirements, and shadowing. Some path loss models are also given here for calculating path loss for both LOS and NLOS cases.

Keywords: design challenges of 60 GHz band, millimetre wave propagation, path loss models, 5G technology, 60 GHz communication ________________________________________________________________________________________________________ I.

INTRODUCTION

Mobile communication has become important part of everyone’s life. The increasing popularity of mobile communication suggests that the demand for mobile broadband will continue to grow in the future. Ultra-High Frequency (UHF) band with frequencies around 300 MHz –3 GHz has been used by almost all commercial radio communications including AM/FM radio, TV, cellular, satellite communication, GPS, and Zigbee/Bluetooth. But with the increasing demand of service this band has become crowded so it is necessary to find another solution for high spectral efficiency.60 GHz band has some attractive features which can provide high spectral efficiency with high user density.

In future, 60 GHz band will provide us a great opportunities for circuits, antenna, and communication engineers by providing high speed data rate up to several tens of gigabits per second and it will allow us uncompressed high-definition media transfers.

[1] This 60 GHz band wireless communication can be implemented by semiconductor technology. Existing WLAN functional at 2.4 GHz and 5 GHz possess a maximum bandwidth of 83.5 MHz and offer a maximum data rate of 100 Mbps. In contrast, the bandwidth available at 60 GHz frequency band is 7 GHz. [5] II. REVIEW OF PAPERS Theodore S. Rappaport, James N. Murdock, Felix Gutierrez, “State of the Art in 60-GHz Integrated Circuits and Systems for Wireless Communications”, IEEEE proceedings, august 2011: In this paper authors have given us an overview of the technological advancement in millimeter-wave (mm-wave) circuit components, antennas, and propagation that will soon allow 60-GHz transceivers to provide such a high data rate up to several tens of gigabit per seconds for wireless communication data transfers in the consumer marketplace. In this paper research process has been shown from different literatures of different wireless system components like radio frequency power amplifiers (PAs), low noise amplifiers (LNAs), mixers, voltage controlled oscillators (VCOs), and analog to digital converters (ADCs) by using different graphs and tables. To implement low cost highly integrated 60 GHz system authors have mainly focused on silicon based technologies.

In this paper it is shown that after permission of FCC for using 60 GHz spectrum, excellent process has been made in the area of on-chip antennas, PAs, LNAs, VCOs, mixers, and ADCs, but still progress is needed in the areas of antenna integration, lower power components, improved baseband and beam forming processing. [1] Current status of improvement and technologies used in different components in 60 GHz transceivers is discussed here.

Farooq Khan, Zhouyue Pi and Sridhar Rajagopal,”Millimeter-wave Mobile Broadband with Large Scale Spatial Processing for 5G Mobile Communication”, IEEE proceedings, October 2012: In this paper millimeter wave band mainly considered as a one solution of 5G cellular system due to its main two advantages of greater spectrum availability and large beam forming gain in small form factors. Current technologies used by our 4G LTE All rights reserved by www.ijste.org

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A Technical Review on Design Challenges of 60 GHz Wireless Communication System (IJSTE/ Volume 2 / Issue 08 / 018)

system are OFDM, MIMO, Turbo Code, and Hybrid ARQ. But further improvements in spectral efficiencies are extremely challenging. One possibility for increasing system capacity is to reduce cell sizes, but this process is also limited due to several cost factors such as site-acquisition, equipment installation, and backhaul provisioning.[2] Millimeter wave technology have already been used for long range point to point communication purpose. But components used in these systems are very bulky and needed too much handling power so it cannot be implemented for mobile communication.

Main challenge is path loss in designing of this system for mobile communication. Path loss is given by following formula. [2] Lfsl =32.4+ 20 log10f + 20 log10R Where Lfsl is the free-space loss in dB, f is the carrier frequency in GHz, and R is the distance between the transmitter and receiver in meters. [2] The authors have analyzed millimeter wave technology and proposed millimeter-wave mobile broadband (MMB) system for 5G mobile communication that can perform 10-100 times better than current 4G LTE mobile communication system due to large bandwidth available at such a high frequency. The challenges can be met by designing new robust system designs and network topologies and developing new technologies supporting hybrid large scale spatial processing with digital and RF beam forming for 100’s of antenna elements. [2] Nektarios Moraitis,” Indoor Channel Measurements and Characterization at 60 GHz for Wireless Local Area Network Applications”, IEEE transaction on antenna and wave propagation, VOL. 52, NO. 12, December 2004: In this paper authors have derived path loss measurements and effect of people as an obstruction. Path loss measurements are made for both LOS and NLOS cases. Finally they concluded that dynamic range of fading is 8.8 dB in normal environment which is increased to 35 dB when person moves between the transmitter and receiver. [3] The reason behind why this band is good for WLAN is its spectrum efficiency and greater capacity due to atmospheric attenuation and isolation provided by this band. For small range of communication, effect of oxygen attenuation is very less so can be neglected.

Path loss models for both LOS and NLOS cases for indoor environment are given by following relationship.

A model for predicting path loss for LOS topographies can be described as [3]: L (d) =Lfs (d0) +10n log10 (d/d0) [3] Where L(d) is the average path loss value (in decibels) at distance between transmitter and receiver, Lfs (d0) is the free-space path loss (in decibels) at a reference distance d0 and n is the path loss exponent.

Fig. 1: Scatter plot of the measured path loss values for LOS locations. [3]

Path loss model for NLOS topographies [3]: L (d) =Lfs (d0) +10n log10 (d/d0) +∑ Koi Li [3] Where, for specific model: n=2, d=1.5, Koi = number of penetrated obstructions, Loi is the attenuation due to i’th type of obstruction.

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A Technical Review on Design Challenges of 60 GHz Wireless Communication System (IJSTE/ Volume 2 / Issue 08 / 018)

Fig. 2: Scatter plot of the measured path loss values for NLOS locations [3]

Sundeep Rangan, Theodore S. Rappaport, "Millimeter-Wave Cellular Wireless Networks: Potentials And Challenges”, IEEE Proceedings, March 2014: In this paper authors have suggested that mmW system will offer greater gain than any currently available 4G cellular networks but this system will need some requirements like highly directional transmission, isolation between the two links, synchronization, channel structure that will provide low value of loss. For the solution of these problems they have given solution of using adaptive beam forming, multihop relaying, heterogeneous network architectures and carrier aggregation. [4] Some of the key challenges for mmW cellular system that are discussed in this paper are listed below.

- Path loss: Higher frequencies of mmW system will result in high path loss as per friis’ transmission law.

- Shadowing: Signals of this band are highly susceptible to shadowing. For example human body can produce 25-30 dB loss in system.

- Rapid channel fluctuations and intermittent connectivity: The channel will change in the order of hundreds of microseconds due to very small coherence time.

- High power consumption: A/D converters for these mmW systems will require high amount power than current 4G cellular system.

III. SUMMARY OF LITERATURE SURVEY From the above literature survey, we can conclude that 60 GHz band will have some very attractive features for cellular communication like very high speed data rate of several tens of gigabits per second, large bandwidth, small form factors of antenna, less interference between the adjacent links and reduced cost for high capacity. The atmospheric absorption properties of 60 GHz band will provide us opportunities for both long and short range communication. [1] Despite the advantages of 60 GHz band, there are a number of challenges for realization of this 60 GHz networks. Main key challenge is path loss for designing this system. Another design challenges are requirement of high amount of power, shadowing, channel fluctuation, multiuser coordination. If such a transceivers can be made which can overcome these challenges, then over the next decade, this advanced mmW system will greatly impact the way people consume media and how wireless networks and systems are designed and deployed. [1]

REFERENCE [1] [2]

Theodore S. Rappaport, James N. Murdock, Felix Gutierrez, “State of the Art in 60-GHz Integrated Circuits and Systems for Wireless Communications”, IEEEE proceedings, august 2011.

Farooq Khan, Zhouyue Pi and Sridhar Rajagopal,”Millimeter-wave Mobile Broadband with Large Scale Spatial Processing for 5G Mobile Communication”, IEEE proceedings, October 2012

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A Technical Review on Design Challenges of 60 GHz Wireless Communication System (IJSTE/ Volume 2 / Issue 08 / 018) [3] [4] [5] [6] [7]

Nektarios Moraitis,” Indoor Channel Measurements and Characterization at 60 GHz for Wireless Local Area Network Applications”, IEEE transaction on antenna and wave propagation, VOL. 52, NO. 12, December 2004. sundeep rangan, Theodore s. Rappaport, "Millimeter-wave cellular wireless networks: Potentials and challenges”, IEEE proceedings, march 2014.

Anuj kumar, T. Rama Rao,” Analysis of planning and deployment issues for short range gigabit radio’s at 60 GHz”, International conference on Communication and Signal Processing, April 2013.

Upamanyu Madhow,” Networking at 60 GHz: the Emergence of Multi Gigabit Wireless”, IEEE journal, 2009.

Theodore S. Rappaport, “wireless communications”, 2nd edition, PHI publications, 2008.

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